Title

Ultraviolet Spectroscopic Study of Ferric Hydroxide Complexation

Authors

Robert H. Byrne, University of South FloridaFollow
Dana R. Kester, University of Rhode Island

Document Type

Article

Publication Date

1978

Keywords

Ferric, hydrolysis, ionic strength, temperature, enthalpy, ferric hydroxide, ultraviolet, spectroscopic

Digital Object Identifier (DOI)

https://doi.org/10.1007/BF00662897

Abstract

Ultraviolet absorbance spectra of ferric ions in 0.68m NaClO₄ were studied as a function of pH at 4.0, 14.9, and 25.0°C. The results provided an evaluation of the stability constant for the formation of FeOH²⁺ which is *β₁=[FeOH ⁺][H ⁺]/[Fe ³⁺]. The enthalpy change for the reaction Fe³⁺+H₂O⇌ FeOH²⁺+H⁺ was calculated as 10.0±0.3 kcal-mole⁻¹. Increasing temperature was also found to promote the reaction Fe³⁺+2H₂O⇌ Fe(OH) ⁺₂ +2H⁺. Our results were combined with the results of other to produce an expression describing the first hydrolysis equilibrium at ionic strengths between 0 and 3m and temperatures between 4.0 and 45.0°C at 1 atm total pressure. At 25°C and 0.68m the ionic strength *β₁=1.90×10^-3

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Solution Chemistry, v. 7, p. 373-383

Scholar Commons Citation

Byrne, Robert H. and Kester, Dana R., "Ultraviolet Spectroscopic Study of Ferric Hydroxide Complexation" (1978). Marine Science Faculty Publications. 1660.
https://digitalcommons.usf.edu/msc_facpub/1660